Increased calcium in carrots by expression of an Arabidopsis H+/Ca2+ transporter.

We demonstrate that carrots expressing the Arabidopsis H⁺/Ca²⁺ transporter CAX1 (Cation Exchanger 1) contained up to 50% more calcium (Ca) than plants transformed with control vectors. The GAX/-expressing carrots were fertile, and robust plant growth was seen in the majority of the transgenic plants. GAX1-expressing carrots were crossed to a commercial carrot variety to confirm that the increased Ca accumulation was mediated by GAX1-expression, and the increased Ca content was clearly correlated with the transgene. This study suggests that modulation of ion transporters could he an important means of increasing the Ca content of agriculturally important crops. To our knowledge, this study represents the first attempts to use biotechnology to increase the Ca content of an agriculturally important crop. [ABSTRACT FROM AUTHOR]